Buckwheat with mushrooms and mince

Ingredients:
buckwheat: 4 cups (500ml)
mushrooms: 500g
mince: 500g
onion: 3
carrots: 2
garlic: 1 head
(optional) tomato paste: 2 table spoons
(optional) tomato sauce: 2 table spoons
vegetable stock or vegetable stock and water: 8 cups (1000 ml)
oil
salt, pepper
(optional) other spices: a little bit
sour cream (optional): 2 table spoons

Directions:
Cut onion, mushrooms, garlic
Grate carrots

Sautae onion
Add carrots, garlic, mince, mushrooms, tomato paste, tomato sauce
salt, pepper, spices
Add buckweat, stock/water
Cook on low (approximately 20 minutes) under the lid
Add sour cream
Mix and cook few minutes more